Corning Incorporated has developed a process known as the fusion process (e.g., downdraw process) to form high quality thin glass sheets that can be used in a variety of devices like flat panel displays (e.g., flat panel liquid crystal displays). The fusion process is the preferred technique for producing glass sheets used in flat panel displays because the glass sheets produced by this process have surfaces with superior flatness and smoothness when compared to glass sheets that are produced by other methods. The fusion process is briefly described below with respect to FIG. 1 but for a more detailed description reference is made to co-assigned U.S. Pat. Nos. 3,338,696 and 3,682,609 (the contents of these two patents are hereby incorporated by reference herein).
Referring to FIG. 1 (PRIOR ART), there is shown a schematic view of an exemplary glass manufacturing system 100 that uses the fusion process (e.g., downdraw process) to make a glass sheet 105. The glass manufacturing system 100 includes a melting vessel 110, a fining vessel 115, a mixing vessel 120 (e.g., stir chamber 120), a delivery vessel 125 (e.g., bowl 125), a fusion draw machine (FDM) 141 and a traveling anvil machine (TAM) 150. The melting vessel 110 is where the glass batch materials are introduced as shown by arrow 112 and melted to form molten glass 126. The fining vessel 115 (e.g., finer tube 115) has a high temperature processing area that receives the molten glass 126 (not shown at this point) from the melting vessel 110 and in which bubbles are removed from the molten glass 126. The fining vessel 115 is connected to the mixing vessel 120 (e.g., stir chamber 120) by a finer to stir chamber connecting tube 122. And, the mixing vessel 120 is connected to the delivery vessel 125 by a stir chamber to bowl connecting tube 127.
The delivery vessel 125 delivers the molten glass 126 through a downcomer 130 into the FDM 141 which includes an inlet 132, a forming vessel 135 (e.g., isopipe 135), and a pull roll assembly 140. As shown, the molten glass 126 from the downcomer 130 flows into an inlet 132 which leads to the forming vessel 135 (e.g., isopipe 135). The forming vessel 135 includes an opening 136 that receives the molten glass 126 which flows into a trough 137 and then overflows and runs down two sides 138a and 138b before fusing together at what is known as a root 139. The root 139 is where the two sides 138a and 138b come together and where the two overflow walls of molten glass 126 rejoin (e.g., refuse) before being drawn downward by the pull roll assembly 140 to form the glass sheet 105.
The pull roll assembly 140 delivers the drawn glass sheet 105 (which at this point in the process has a curved/bowed shape) to the TAM 150 which includes a flat nosing device 152 and a scoring device 154 that are used to score and separate the bowed glass sheet 105 into distinct pieces of glass sheets 105 (see the enlarged top view of the TAM 150 illustrated in FIG. 1). The scoring device 154 is not used until after the flat nosing device 152 engages the bowed glass sheet 105. The flat nosing device 152 by engaging the bowed glass sheet 105 tends to flatten the bowed glass sheet 105 (this process is known as pressing). Then, the scoring device 154 extends a scoring wheel 156 which scores the glass sheet 105 and also pushes the bowed glass sheet 105 even more against the flat nosing device 152 (this process step is known as ironing). After scoring, the flattened glass sheet 105 is bent in a direction perpendicular to it's original curved surface and separated to create a smaller glass sheet 105 which is shown located below the TAM 150.
The pressing, ironing, scoring and separating processes cause motion in the glass sheet 105 which in turn contribute to the creation of stress variations within the glass sheet 105. There are several problems which can occur whenever the glass sheet 105 is stressed. For example, a stressed glass sheet 105 can distort/warp which is not a desirable situation for the customers. Plus, a large glass sheet 105 may be stressed yet undistorted but then that large glass sheet 105 will later distort/warp when it is subsequently cut into smaller pieces of glass sheets. This is not desirable. Accordingly, there is a need for a device that helps prevent the motion of the glass sheet 105 and helps prevent the creation of stress variation within the glass sheet 105 while the glass sheet is being scored and separated into individual glass sheets. This need and other needs are satisfied by the conformable nosing device of the present invention.